Remember, its THEIR life to live not yours.. you don’t have to agree with their decisions, but you aren’t the ones making them.
My son’s best friend in grade school was the child of 2 lesbians, granted not immediate family, but still.. I don’t recall ever having very deep conversations with him about it all, just was the way his friend’s life was. Now they weren’t radical in your face lesbians which did make it a lot easier, and we never treated them any different than any other couple.
Another couple I know that are doing this, I would not want my children around at all and truly do fear for their son, the one is a completely over domineering anti male dyke, and I feel for their son every time I see him.
I can’t give you answers, but I think you are making more of this than probably there is. You have to make decisions about your life, and your child’s, but you cannot control what others do, and trying to is just wasted energy.
It's about how it will affect her children. If her children see her accepting homosexual behavior and relationships as though they are normal and natural this will affect her children. It is a problem.